We feed her and the yorkie some Science Diet WD due to it being low in fat for the yorkie. We have been using this formula for many years now. My dog is eight years old and going on 9 in June.

Now she is eating both bowls of the food all the time even when I know she is not hungry but she'll go in the kitchen eat the food and I have to refill both bowls up to calm down the yorkie(he doesn't like a empty bowl regardless of what his appetite is lol). She has gained a lot of weight.

What could be the reasons for her eating so much all of a sudden this year? It's about 2 cups of food per bowl. Could they do a vitamin deficiency test on her?